This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Location services that are based on the location of mobile devices, commonly referred to as “assisted navigation systems,” are becoming increasingly widespread. There are currently a variety of assisted navigation systems, including Global Navigation Satellite Systems (GNSS) such as Global Positioning System (GPS), GLObal NAvigation Satellite System (GLONASS) and Galileo. As used herein, “assistance data” may include, but is not limited to, navigation models, time assistance, reference location, atmosphere models, differential corrections, sensor assistance and acquisition assistance. Assistance data can also include, for example, position information, high-accuracy position information, multi-frequency multi-GNSS measurement data, sensor measurements, route information and waypoint information. Assistance data for assisted navigation systems have been specified and standardized for cellular systems. The delivery of such assistance data can be built on top of cellular system-specific control plane protocols. Such protocols include, for example, the radio resource location services protocol (RRLP) for Global System for Mobile Communications (GSM) networks, the radio resource control (RRC) layer of layer 3 in wideband code division multiple access (WCDMA) networks, and IS-801 for code division multiple access (CDMA) networks, standardized in the 3rd Generation Partnership Project (3GPP) and 3GPP2 standards.
The Open Mobile Alliance (OMA) has defined a user plane protocol referred to as Secure User Plane Location (SUPL). SUPL employs user plane data bearers for transferring location assistance information, such as GNSS assistance data and for carrying positioning technology-related protocols between a terminal, e.g., a mobile communication device, and its operating network. SUPL is intended to be an alternative and, at the same time, a complement to existing standards based on signaling in the mobile network control plane. SUPL assumes that a mobile network or other network can establish a data bearer connection between a terminal and some type of location server. The use of a user plane protocol can be particularly beneficial in the case of IP networks where the data bearer is available by nature. SUPL utilizes existing control plane standards whenever possible.
The utilization of SUPL involves the wrapping of control plane protocols in order to move the signaling functionality of location assistance information from the control plane to the user plane. However, SUPL is reliant upon the underlying system-specific control plane protocols. This approach also moves the actual positioning from SUPL to the underlying subprotocols.
While SUPL and other location protocols support a variety of location features, some advanced positioning technologies, as well as LBSs require, however, continuous assistance data delivery between, for example, a terminal and a network. This type of streaming is not readily supported by existing location protocols. As used herein, “streaming” refers to transferring, in a sequence, messages containing the same data type within a single session. For example, in the case of streaming carrier phase measurements from one SUPL-enabled terminal to another SUPL-enabled terminal, the measurement must be continuous, i.e. the GNSS receiver must not be shut down between reports. This implies that the positioning session is kept open over the entire measurement period. This is in contrast to the “periodic reporting” that is defined in SUPL, where every periodic report initiates a new SUPL session.